The present invention relates in general to mine roof supports and, more particularly, to lateral gap seals therefor.
It is known to employ seals for sealing off the gaps between adjacent roof supports in an underground mine working. These seals normally take the form of plates on the roof-engaging girders or structure and on the goaf-shields where provided. The plates on adjacent supports engage one another between the supports. Such an arrangement, although primarily intended for gap sealing, also tends to align and guide the supports on one another during shifting. It is known to employ piston and cylinder units for displacing the plates to adjust the plates and ensure good sealing and guiding contact. It is also known to employ springs which act to bias the plates apart so they can maintain contact even if the piston and cylinder units should fail during operation. An example of a known support employing lateral seals is described in German Pat. No. 2,310,757.
Hitherto, it has proved difficult to assemble the structural components of a roof support having lateral seals on its roof frame and goaf shield in situ primarily because the seal plates slidably and pivotably overlap between the roof frame and the goaf shield. Special accessories have thus been adopted to hold the plates of the roof frame or goaf shield in against the spring biasing force until the roof frame and goaf shield have been assembled together. This solution has not been wholly satisfactory, however.
A general object of the present invention is to provide an improved support and improved gap sealing means therefor.